Device and method for manufacturing stator of ultra high speed induction motor

Abstract

An apparatus and method for fabricating a stator of a super-high-speed induction motor, in which the process of loading a stator on which a coil is completely wound into a mold, injecting a functional resin into a chamber, converting the inside of the chamber into the vacuum state, and pressurizing the inside of the chamber is carried out so that bubbles are removed from the inside and the surface of the functional resin and the functional resin is completely filled between the inner circumference of the stator and the inner circumference of the mold, thereby maximizing heat conductivity and insulation, preventing the stator from deteriorating, and improving the performance and endurance of the super-high-speed induction motor. In addition, since the vacuum step and the pressurizing step include heating the mold, in the vacuum step, the viscosity of the functional resin can be decreased so that the process of removing gas inside the stator can be efficiently performed and the solidification time of the functional resin can be decreased so that the working time can be decreased, and in the pressurizing step, the molding that is under pressing force is completely solidified. Furthermore, the height of the receiving section of the mold and the height of the central shaft are adjusted so that the winding section of the stator is completely immersed, and the chamber is provided with a vacuum tube and a pressurizing tube in order to facilitate the step of injecting the functional resin and the pressuring step. The method includes (a) loading a stator having a coil, which is completely wound on a core, into a mold, (b) injecting a functional resin into the mold so that a winding section of the stator is immersed, (c) inserting the mold, into which the functional resin is injected, into a closed chamber, (d) removing bubbles by converting the inside of the chamber into a vacuum state through a vacuum tube, which is provided in the chamber, so that the functional resin is filled across the entire portions of the stator, including the core and the coil, and between the inner circumference of the stator and the inner circumference of the mold, and (e) removing bubbles by increasing the gas pressure in the chamber, so that the functional resin is filled across the entire portions of the stator, including the core and the coil, and between the inner circumference of the stator and the inner circumference of the mold.

What is claimed is: 
     
       1. An apparatus for fabricating a stator of a induction motor, the stator formed by a coil surrounding a core and fixed thereto by a functional resin, comprising:
 a mold receiving the stator and including
 a cylindrical can-shaped receiving section having a height greater than that of a winding section of the stator such that the stator with the coil completely wound on the core is completely received therein, and 
 a cylindrical central shaft fixed on a central portion of a bottom surface of the receiving section and having a height greater than that of the receiving section for preventing the functional resin from sticking to an upper end of the cylindrical central shaft; and 
 
 a chamber receiving the mold therein and comprising
 a heater fixed in a bottom wall portion of the chamber for heating the mold, 
 a vacuum tube provided in an upper side of the chamber for evacuating the interior of the chamber, and 
 a pressurizing tube separate from the vacuum tube in the upper side of the chamber for pressurizing the chamber with a gas, thereby removing residual bubbles inside and on a surface of the functional resin. 
 
 
     
     
       2. A method for fabricating a stator of an induction motor, comprising:
 (a) preparing a mold which includes a cylindrical can-shaped receiving section and a cylindrical central shaft, the cylindrical central shaft being fixed to and projecting from a central portion of a bottom surface of the mold and having a height greater than that of the receiving section, for preventing a functional resin from sticking to an upper end of the cylindrical central shaft; 
 (b) loading a stator having a coil and a core, into the mold; 
 (c) injecting the functional resin into the mold so that the stator is immersed therein; 
 (d) placing the mold, with the stator and the functional resin therein, into the chamber; 
 (e) opening a vacuum tube provided in an upper side of the chamber and closing a pressurizing tube provided in the upper side of the chamber, and evacuating the chamber through the vacuum tube, the pressurizing tube being separate from the vacuum tube, and then opening the pressurizing tube and closing the vacuum tube and injecting a gas into the chamber through the pressurizing tube to increase a gas pressure inside the chamber, so that the functional resin fills all space between the core and the coil and between an inner circumference of the stator and an inner circumference of the mold; and 
 (f) during the step (e), heating the mold in the chamber by a heater fixed in a bottom wall portion of the chamber, in order to decrease a viscosity and a solidification time of the functional resin.